Quinine Level
Overview
Quinine level measures the concentration of quinine, an alkaloid derived from cinchona bark, in blood to assess therapeutic drug monitoring and toxicity risk. It functions primarily as an antimalarial agent by interfering with parasite protein synthesis and has secondary antiarrhythmic and muscle relaxant effects. High levels may indicate overdose, renal impairment, or drug accumulation leading to cinchonism (tinnitus, visual disturbances), while low levels suggest subtherapeutic dosing or malabsorption; it is clinically useful for guiding malaria treatment, preventing toxicity in vulnerable patients, and managing quinine-induced adverse effects.
Clinical Use Cases
- Therapeutic drug monitoring during severe malaria treatment.
- Assessing toxicity in overdose or impaired clearance cases.
- Evaluating treatment failure in resistant Plasmodium infections.
- Monitoring in patients with renal or hepatic dysfunction.
- Managing cardiac arrhythmias (historical use).
Specimen Types
- Serum.
- Plasma.
- Whole blood.
Measurement Methods
- High-performance liquid chromatography (HPLC) with UV or fluorescence detection.
- Liquid chromatography-tandem mass spectrometry (LC-MS/MS).
- Immunoassays (limited availability).
Test Preparation and Influencing Factors
- No fasting required.
- Time collection: peak levels 1-3 hours post-dose; trough before next dose.
- Impaired renal function prolongs half-life (8-14 hours normally).
- Drug interactions with cimetidine, ketoconazole increase levels.
- Avoid grapefruit juice; pH-dependent absorption.
Synonyms
- Quinine plasma concentration.
- Quinoline alkaloid level.